I just got an idea for AV. How about making it a pure passive, when hit with an unavoidable attack you have a x% chance to transform your felflame into a more powerful spell dealing z% more damage and maybe deal an additional effect based on spec.
The idea here is to make it a retaliation ability that while a passive talent, isnt in it self passive. AV in its current for is boring because the only way to actively make it work for you is to intentionally take more damage. By making it give you a player controlled retaliation ability you let the talent do something active without bloating your bars with another keybind.
Making it transform Felflame into a retaliation spell prevents you from auto retaliating if it was say a basic filler spell that you probably would have hit anyway. This should have the potential to make it useful in pvp and pve (though %change would need to be tweaked for pvp)